For the next two days, Chronos is giving away StickyBrain for free, its personal productivity application that features a “sticky note” interface. “StickyBrain is one of the best kept secrets on the Mac and we want to let the public in on the secret. We believe that once users get a taste for StickyBrain, they’ll be hooked,” Robert McCullough, Product Manager at Chronos, explained in a press release. StickyBrain is a carbon application and normally sells for US$34.99.